Pre-gapped distributor points



Sept. 21, 1965 MUSGRAVE 3,207,863

PRE-GAPPED DISTRIBUTOR POINTS Filed May 16, 1962 3 Sheets-Sheet 1 E ar/e Musgrave 1 N VEN TOR v p 21, 1965 E. MUSGRAVE 3,207,863

PRE-GAPPED DISTRIBUTOR POINTS Filed May 16, 1962 3 Sheets-Sheet 2 E ar/e Musgra we 1 N VljN TOR.

p 1955 E. MUSGRAVE 3,207,863

PRE-GAPPED DISTRIBUTOR POINTS Filed May 16, 1962 3 Sheets-Sheet 5 E ar/e Musgra we 1 N VEN TOR.

United States Patent 3,207,863 PRE-GAPPED DISTRIBUTOR POINTS Earle Musgrave, 4823 Stratford Road, Los Angeles, Calif. Filed May 16, 1962, Ser. No. 195,059 13 Claims. (Cl. 20030) This invention relates to a novel and useful pregapped distributor point assembly and more specifically to a distributor point assembly which may be constructed in a manner so that the manufacturer may determine the maximum point gap which may be effected by the ignition point assembly after it has been properly mounted within a distributor.

In conventional point assemblies one arm of the point assembly is fixedly secured in adjusted rotated position relative to a pivot post carried by a breaker plate of the distributor on which the point assembly is mounted. The other point arm has one end pivotally associated with the pivot post of the breaker plate and is insulated relative thereto and from the other arm. The free end of the arm which is insulated from the post is movable toward and away from the free end of the other arm and the free ends of the arms are provided with opposing contacts which are movable into engagement with each other upon relative movement of the free end of the movable arm toward a corresponding end of the fixed arm.

In setting a distributor point assembly for the proper gapping between the opposing contacts, the cam on the distributor shaft is rotated to a position with one of its high points engaged with the rubbing block carried by the movable arm. Then, the stationary arm is adjustably rotatably positioned relative to the pivot post so that a predetermined special relationship will exist between the opposing contacts.

With the development of assembled distributor point assemblies which may be mounted within a distributor housing in one piece, the replacement and gapping of new distributor points is relatively easy. However, after a distributor point assembly has 'been in use for several thousand miles of operation or its equivalent, there is a build-up on one of the opposing contacts and a cor responding depression formed in the other contact. As the feeler gauges which are utilized to gap distributor point assemblies are panel-like, if a feeler gauge i positioned between a pair of opposing contacts which have been in use for several thousand miles, the build-up on the one contact will cause a relatively large percentage of error to occur when attempting to properly gap the opposing contacts. Although ignition point assemblies are often removed for inspection after relatively short periods of operation, they are not always replaced as replacement is not usually required after short periods of operation. However, it is still necessary to regap the contacts of conventional ignition point assemblies and this become very difficult if there has been a build-up on one contact and a corresponding depression formed on the other.

It is accordingly, the main object of this invention to provide a means whereby the maximum special relationship of the contacts of a distributor point assembly may be pre-set by the manufacturer. This will further simplify the installation of new ignition point assemblies in distributors and will also greatly facilitate the replacement of used but serviceable ignition point assemblies in distributors.

A further object of this invention, in accordance with the immediately preceding object, is to provide an ignition point assembly including means whereby the maximum spacial relationship between the contacts thereof may be predetermined and set by the manufacturer of the point assembly at the correct spacial relationship in order that ignition point bounce due to high speed operation of 3,207,863 Patented Sept. 21, 1965 ice the distributor will be limited inasmuch as once the distributor cam has opened the contacts the desired maximum amount, the inertia of the movable contact will be ineffective to further increase the spacial relationship of the contacts.

A final object to be specifically enumerated herein is to provide an ignition point assembly in accordance with the preceding objects which will conform to conventional forms a manufacture, to be of simple construction and easy to use so as to provide a device that will be economically feasible, long-lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, .and in which:

FIGURE 1 is a top plan view of a conventional type of ignition distributor shown with the ignition point assembly of the instant invention mounted therein;

FIGURE 2 is a side elevational view of the ignition point assembly illustrated in FIGURE 1;

FIGURE 3 is a fragmentary enlarged top plan view of the assemblage shown in FIGURE 1 but showing the distributor cam rotated slightly;

FIGURE 4 is a perspective view of the abutment member of the point assembly illustrated in FIGURE 3; and

FIGURES 5, 7, 9 and 11 are top plan views of conventional distributors having further modified forms of the ignition point assembly mounted therein; and

FIGURES 6, 8, 10 and 12 are perspective views of the abutment members of the ignition point assemblies illustrated in FIGURES 5, 7, 9 and 11, respectively.

Referring now more specifically to the drawings, the numeral 10 generally designates a conventional type of distributor which includes a housing 12 having a breaker plate 14 mounted therein for oscillation about the axis of rotation of the cam 16 which is centrally disposed relative to the breaker plate 14. A conventional vacuum advance assembly generally referred to by the reference numeral 18 is provided and includes an actuating arm 20 whose free end is pivotally secured to the breaker plate 14 by means of pivot pin 22.

The ignition point assembly of the instant invention is generally referred to by the reference numeral 24 and includes a pair of pre-assembled first and second arms 26 and 28 which have one pair of adjacent ends pivotally secured together and pivotally supported from the breaker plate 14 by means of a pivot post 30 projecting upwardly therefrom. While the arms 26 and 28 are p-re-assembled, it is to be understood that the present invention could also be used with point assemblies having separable arms.

The first arm 26 is provided with an arcuate slot 32 whose center of curvature coincides with the pivot post 30 and the breaker plate 14 is provided with a threaded bore (not shown) in which the shank (not shown) of the locking screw 34 is threadedly engaged. The shank of the locking screw 34 is slidably disposed in the slot 32 whereupon the free end of the first arm 26 which has a first contact 36 thereon may be adjustably positioned about the pivot post 30.

The second arm 28 is provided with a rubbing block 38 which is disposed in sliding contacting relation with the cam 16 and the second arm 28 is normally resiliently urged toward a position with the rubbing block 38 in engagement with the cam 16 by means of a leaf spring 40 which is secured at one end to the rubbing block 38 and at the other end to an upstanding mounting flange 42 carried by the first arm 26 by means of an insulated terminal post 44.

The terminal post 44 is mounted from the flange 42 and is insulated therefrom in any convenient manner. A capacitor 46 is supported from the mounting plate 14 by means of a fastener 48 and its lead 50 is connected to the terminal post 44 as is conventional.

The preceding description of the embodiment illustrated in FIGURES 1 and 3 is conventional.

The ignition point assembly 24 includes an abutment member 54 which is constructed of dielectric material and supported from a free end of a threaded shank member 56 that is threadedly engaged in a threaded bore 58 formed in the flange 42. A jam nut 60 is provided and is also threadedly engaged with the threaded shank member 56 so as to retain the latter in adjusted position relative to the flange 42.

It may be seen that the abutment member 54 is disposed for engagement by the second arm 28 on whose free end there is provided a second contact 62 and that the abutment member 54 will limit movement of the second contact 62 away from the first contact 36. In operation, when it is desired to install a new set of point contacts, the point assembly 24 may first be engaged with the pivot post 30 as is conventional. Then, the locking screw 34 may be turned until it is snug and yet not tight; The first arm 26 may then have its free end pivoted toward the cam 16. Thereafter, the cam 16 may be rotated until one of its points 66 is engaged with the rubbing block 38. The movement of the rubbing block 38 away from the axis of rotation of the cam 16 by the positioning of the high point 66 in engagement with the rubbing block 38 will pivot the free end of the second arm 28 away from the axis of rotation of the cam 16 until the backside of the arm 28 engages the abutment member 54 whereupon any further movement of the free end of the arm 28 away from the axis of rotation of the cam 16 will also swing the free end of the first arm 26 away from the axis of rotation of the cam 16. Then, the locking screw 34 may be tightened so as to retain the first arm 26 in adjusted position relative to the pivot post 30.

It is, of course, to be understood that the abutment member 54 has been pre-set in position relative to the first arm 26 by the manufacturer so that the gap or spacial .relationship between the contacts 36 and 62 will be as desired when the rubbing block 38 is engaged with the high point 66 and the arm 28 is engaged with the abutment member 54. Then, as the cam rotates, the second arm 28 will be oscillated toward and away from engagement with the first contact 36. In addition to providing a means for pre-setting the gapping of the contacts 36 and .62, it will be noted that any tendency of the free end of the second arm 28 to swing further away from the contact 36 then desired because of the inertia of the second arm 28 operating at high speeds will be prevented by engagement of the abutment member 54 with the backside of the arm 28.

With attention now directed to FIGURES and 6 of the drawings there will be seen a modified form of point assembly generally referred to by the reference numeral 68 which is very similar to the point assembly 24 and differs therefrom only in the positioning of its abutment member. The distributor generally referred to by the reference numeral 70 in which the point assembly 68 is secured is substantially identical to the distributor 10.

The abutment member 72 of the assembly 68 is mush room shaped and is supported by means of a threaded shank member 74 not unlike the shank member 56. The threaded shank member 74 is also threadedly engaged with the corresponding first arm. A threaded bore (not shown) is secured in the flange 76 of the first arm 78 and the shank member 74 also has a jam nut 80 threadedly engaged therewith.

The operation of the point assembly 68 and its adjustment during installation within the distributor 70 is substantially the same as the point assembly 24 as will be apparent.

With attention now directed to FIGURES 7 and 8 of the drawings, there will be seen a modified form of the distributor generally referred to by reference numeral 82 which is substantially identical to the distributors 10 and 70 with the exception that the terminal post 84 thereof is supported and insulated from the housing 86 of the distributor 82 as opposed to the first arm 88 of the point contact assembly 90. The second arm 92 of the contact assembly includes a leaf spring 94 which resiliently urges the second contact 96 on its free end into engage ment with the first contact 98 carried by the first arm 88. The end of the leaf spring 94 remote from the second arm 92 is secured to the terminal post 84.

The operation of the distributor 82 is however substantially identical to the operation of the distributors 10 and 70 and it may be seen that the first arm 88 includes a flange 100 which is provided with a suitable threaded bore (not shown) in which a threaded shank portion 102 of a mounting screw 104 is engaged. The abutment member 106 is generally L-shaped and includes a first leg 108 which has a longitudinal slot 110 formed therein and second leg 112. A threaded shank portion 102 of the screw fastener 104 is slidably received in the slot 110 and leg 112 overlie the backside of the second arm 92 for determining its maximum spacial relationship relative to the first contact 98. The fastener 104 may, of course, be loosened if desired in order to change the setting of the maximum spacial relationship between the contacts 96 and 98 and it is also to be understood that the abutment members 54 and 72 may also be adjusted.

The operation of the point assembly 90 in the distributor 82 is substantially identical to that of the point assembly 68 as will be apparent.

With attention now directed to FIGURES 9 and 10, there will be seen a further modified form of point assembly generally referred to by the reference numeral 114 which is substantially identical to the point assembly 91] and is mounted within a distributor 116 substantially identical to the distributor 82. The point contact assembly 114 differs from the point contact assembly 90 only in that the threaded shank portion 118 of the fastener 120 is threadedly engaged in a threaded bore (not shown) in the first arm 122 of the assembly 114 and has a cylindrical abutment member 124 eccentrically mounted thereon for engagement by the backside of the second arm 126 of the point assembly 114. The operation of the point assembly 114 is substantially identical to that of the point assembly 90 and the maximum spacial relationship between the first and second contacts 126 and 128 may be readily adjusted by loosening the fastener 120 and rotating the abutment member 124 relative thereto the desired amount before again tightening the fastener 120.

With attention now directed to FIGURES 11 and 12 of the drawings, there will be seen a still further modified form of point assembly generally referred to by the reference numeral 130 which is substantially identical to the point contact assembly 114 excepting that the abutment member 132 thereof is oblong in plan and is provided with an elongated longitudinally extending slot 134 through which the threaded shank portion 136 of the fastener 138 projects. The free end of the threaded shank portion 136 is of course threadedly engaged in a suitable threaded bore (not shown) formed in the first arm 140 and in this manner, the abutment member 132 may be adjusted into position relative to the first arm 140 so as to limit the maximum spacial relationship between the first and second contacts 142 and 144. The distributor 146 in which the point assembly 130 is mounted is substantially identical to the distributors 82 and 116 illustrated in FIGURES 7 and 9. Additionally, the operation of the point assembly 130 is substantially identical to the operation of the point assembly 114 with the exception of the manner in which the abutment member 132 thereof is adjusted.

In any event, it may be seen that each of the abutment members disclosed herein is supported for adjustment relative to and from the corresponding first arm and independently of the terminal post of that point assembly. Accordingly, the abutment members of each of the forms of point assemblies disclosed herein may be adjusted independently of any adjustment of or connection to the terminal post of the corresponding distributor. Therefore, it may be seen that the various forms of point assemblies disclosed herein may be readily removed and replaced without interfering with the pre-set maximum spacial relationship of the first and escond opposing contacts thereof unless adjustment of these contacts is deemed necessary.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with an ignition distributor including a breaker plate, an ignition point assembly, said breaker plate including a conventional pivot post, said ignition point assembly comprising first and second arms independently pivotally mounted as a unit at one pair of ends on said post for independent movement of the other pair of ends toward and away from each other and having on said other pair of ends first and second opposing contacts respectively engageable with each other upon relative movement of said other pairs of ends together, said first arm and said plate including coacting means securing said first arm to said plate in adjusted rotated position relative to said plate, an insulated terminal post supported from said distributor, means electrically connecting said second arm to said terminal post, abutment means carried by said first arm independently of said terminal post and insulatively supported from said first arm, said abutment means being engageable :by said second arm for limiting movement of the free end of said second arm away from the corresponding end of said first arm.

2. The combination of claim 1 wherein said abutment means is adjustable relative to said first arm.

3. The combination of claim 1 wherein said terminal post is supported directly from said first arm.

4. The combination of claim 1 wherein said distributor includes a housing in which said plate is supported, said terminal post being supported directly from said housing.

5. The combination of claim 1 wherein said abutment means includes a block of dielectric material supported from said first arm for adjustment toward and away from the free end of said second arm.

6. The combination of claim 1 wherein said abutment means includes a threaded shank member threadedly engaged with said first arm and disposed at substantially right angles to said pivot and including a free end portion on which there is a block of dielectric material engageable by the free end of said second arm,

7. The combination of claim 6 wherin said shank member is disposed in the path of movement of said second arm.

8. The combination of claim 1 wherein said abutment means includes a threaded shank member threadedly engaged with said first arm, generally paralleling said pivot post and disposed in the path of movement of said second arm, a body of dielectric material disposed about said shank member and engageable by the free end of said second arm.

9. The combination of claim 8 wherein said body of dielectric material is eccentrically mounted on said shank member.

10. The combination of claim 1 wherein said abutment means includes a threaded shank member threadedly engaged with said first arm, generally paralleling said pivot post and disposed in the path of movement of said second arm, a body of dielectric material disposed about said shank member and engageable by the free end of said second arm, said body of dielectric material being adjustable radially of said shank member.

11. The combination of claim 1 wherein said abutment means includes a threaded shank member threadedly engaged with said first arm and disposed at substantially right angles to said pivot post and including a free end portion on which there is a block of dielectric material engageable by the free end of said second arm, said shank member being disposed out of the path of movement of said second arm.

12. The combination of claim 11 wherein said shank member extends in a direction generally paralleling the direction of movement of said free end of said second arm when said contacts are spaced slightly apart.

13. The combination of claim 1 wherein said abutment means includes a threaded shank member threadedly engaged with said first arm and disposed at substantially right angles to said pivot post and including a free end portion on which there is a block of dielectric material engageable by the free end of said second arm; said shank member being disposed out of the path of movement of said second arm, and said shank member extending in a direction at substantially right angles to the direction of movement of said free end of said second arm when said contacts are spaced slightly apart.

References Cited by the Examiner UNITED STATES PATENTS 1,691,870 11/28 Gadke 200-30 2,161,388 7/39 Dame 200-166 2 ,266,156 12/41 Brauer 200-166 2,674,663 4/54 Kitts 200-31 2,797,269 6/57 Buck et al. 200-31 2,820,858 l/58 Tompkins 200-30 2,914,625 11/59 Heveran 200-166 BERNARD A. GILHEANY, Primary Examiner,

RICHARD M. WOOD, Examiner, 

1. IN COMBINATION WITH AN IGNITION DISTRIBUTOR INCLUDING A BREAKER PLATE, AN IGNITION POINT ASSEMBLY, SAID BREAKER PLATE INCLUDING A CONVENTIONAL PIVOT POST, SAID IGNITION POINT ASSEMBLY COMPRISING FIRST AND SECOND ARMS INDEPENDENTLY PIVOTALLY MOUNTED AS A UNIT AT ONE PAIR OF ENDS ON SAID POST FOR INDEPENDENT MOVEMENT OF THE OTHER PAIR OF ENDS TOWARD AND AWAY FROM EACH OTHER AND HAVING ON SAID OTHER PAIR OF ENDS FIRST AND SECOND OPPOSING CONTACTS RESPECTIVELY ENGAGEABLE WITH EACH OTHER UPON RELATIVE MOVEMENT OF SAID OTHER PAIRS OF ENDS TOGETHER, SAID FIRST ARM AND SAID PLATE INCLUDING COACTING MEANS SECURING SAID FIRST ARM TO SAID PLATE IN ADJUSTED ROTATED POSITION RELATIVE TO SAID PLATE, AN INSULATED TERMINAL POST SUPPORTED FROM SAID DISTRIBUTOR, MEANS ELECTRICALLY CONNECTING SAID SECOND ARM TO SAID TERMINAL POST, ABUTMENT MEANS CARRIED BY SAID FIRST ARM INDEPENDENTLY OF SAID TERMINAL POST AND INSULATIVELY SUPPORTED FROM SAID FIRST ARM, SAID ABUTMENT MEANS BEING ENGAGEABLE BY SAID SECOND ARM FOR LIMITING MOVEMENT OF THE FREE END OF SAID SECOND ARM AWAY FROM THE CORRESPONDING END OF SAID FIRST ARM. 